It doesn't look like you have read the Posting Guide (see bottom of email). This not a homework help forum. Please use the assistance provided by your educational institution. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
Andre Cesta <aace...@yahoo.com> wrote: > > >Hi All, I wonder if you can help me with an aparently simple task. I >have been searching examples for this without any luck: #Assume >x<-1:10 #x ranges from 1 to 10. >y<-x*runif(10)+ 1.5*x #y is a linear function of x with some error. >Add uniform error that is scaled to be larger as x values also become >larger #error is proportional to x size, this should cause >heterocedasticity. #I know there are many methods to deal with >heterocedasticity, but in my specific case, I want to use percent >regression to minimize the mean absolute >#percentual error as opposed to regular regression that deals with the >square of the errors. #Question, how to fit a linear model to minimize >this error on the data y ~ x above? >#Please do not use model<-lm(y ~ x....) as this will minimize the >square of the errors, not the mean absolute percent error Best regards, >André Cesta > >______________________________________________ >R-help@r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.